birth weight (bw) is the first trait recorded fllowing birth. it can influence the performance of thecow and as well impact the performance of the calf it,s duringits maturity. to investigate the effect ofa calf,s bw on the performance of holstein dairy cattle in iran, the records gathered between 1967 and2010 were obtained from the iranian animal breeding center. the data were then used to mod...

Using monthly test day records the genetic parameters of Iranian Holstein cattle in first lactation were studied. Data of 277400 test-day milk records from 65320 cows and 2210 sires were analyzed by an animal random regression model using restricted maximum likelihood methodology. The model included herd-test-date, interaction between year-season of calving, days in milk (linear and quadratic) ...

A rapid and simple technique for diagnosis of rotaviral diarrhea is polyacrylamide gel electrophoresis (PAGE) of dsRNA extracted from fecal samples. To determine the electrophoretype of Iranian calf rotavirus, 23 rotaviral positive fecal samples from diarrheic Holstein calves at the age of less than one month in Tehran region were examined. The viral dsRNA was extracted with phenol-chloroform, ...

Bovine genital campylobacteriosis is one of the most economically important diseases of dairy cattleresulting in lowered fertility, embryo mortality and abortion, repeated returns to service, reduced pregnancyrates and extended calving intervals. While the occurrence of repeat breeding syndrome and abortions arereported from many Iranian dairy cattle farms, little information is available regar...

The rumen microbial community in dairy cows plays a critical role in efficient milk production. However, there is a lack of data comparing the composition of the rumen bacterial community of the main dairy breeds. This study utilizes 16S rRNA gene sequencing to describe the rumen bacterial community composition in Holstein and Jersey cows fed the same diet by sampling the rumen microbiota via t...

Bovine tuberculosis is a major economic problem and a potential public health risk. Improved diagnostics like the gamma interferon (IFN-gamma) test with ESAT6 and/or CFP10 could contribute to the control program. We assessed IFN-gamma responses in zebu (Ethiopian Arsi breed) and Holstein cattle kept indoors or in a pasture to tuberculin purified protein derivative (PPD) and an ESAT6-CFP10 prote...

Six Holstein (light-muscled type) and six Belgian Blue bulls (double-muscled type) were fed a finishing diet. Average daily gain was 1.36 kg for the Holstein bulls vs 1.24 kg for the Belgian Blue bulls (P less than .05). Holstein bulls consumed more feed (2.3 vs 1.8 kg/100 kg body weight, P less than .001) than the Belgian Blue bulls. The dressing percentage (55.4 vs 65.8%, P less than .001) an...

The study was carried out in Sahiwal, Holstein Friesian, Jersey and crossbred cattle and Murrah, Bhadwari, Jaffarabadi, Nagpuri and Surti buffaloes maintained at different organized herds to work out the polymorphism at growth hormone locus and study its effect on birth weight. A 223 bp fragment of the gene was amplified and digested with Alu I restriction enzyme. Two alleles, L and V with thre...

Approximately 20% of the beef tonnage produced in the United States is derived from Holsteins, through harvested dairy beef or cull dairy cows (Randy Blach, Cattle-Fax, personal communication). This represents a significant contribution to the U.S. beef supply. More and more large commercial feed yards have seen the opportunity available with feeding Holstein steers. Inherent variation between ...